A father and his one remaining son sit beside the remains of their home in the village of Luofo in eastern Congo. The father, Muhindo Bayonga, lost his three other sons when the FDLR Hutu militia torched his house – and 254 other homes – on Apr. 17.

Luofo, Democratic Republic of Congo — "You see how I am, I cannot fight again," says Mukalayi Senga, a bed-ridden Congolese government soldier, his lower right leg heavily bandaged after it was shattered by a misdirected mortar. "With the small money the Army gave me, I was not able to pay for my children's school fees. Now, I don't know how I will be able to take care of my family at all."

The Congoglese Army's month-long joint offensive with Rwandan troops – invited across the border in a surprise bilateral deal in January – had the FDLR on the run. But now, the desperate militia is terrorizing tribes it had previously lived with peacefully, killing scores of civilians and displacing tens of thousands. Security officials, diplomats, and aid workers are becoming increasingly concerned that lack of payment for soldiers could worsen already low morale and undo recent progress toward rooting out the Hutu militiamen.

Yet Congolese soldiers are being expected to take the fight to a well-organized and ruthless FDLR, which has a long-established presence in eastern Congo. Having fled from Rwanda 15 years ago – where some of its fighters took part in the 1994 genocide that claimed the lives of up to 800,000 Tutsis and moderate Hutus – this militia controls significant mineral resources, such as tin and gold mines. For its core of more than 5,000 remaining fighters, there is little incentive to return home.

Losing momentum

Congo's military is losing the momentum built up during the recent Rwandan intervention. Only 105 Hutu militiamen were repatriated in April, according to figures from the UN. In February, when Rwandan troops were dispersing the militia from deep inside Congo, 586 rebels were bused back to Rwanda.

And the FDLR appears to be regaining the upper hand.

"Although the military operations pushed them out of their bases, in a number of places FDLR combatants have returned or remain very close by," says Anneke Van Woudenberg, senior Africa researcher for Human Rights Watch. This includes parts of Walikale territory, which is rich in tin and gold, and Lubero territory, which has over 100 gold mines, according to a Western official who spoke on condition of anonymity.

A new strategy of terror

In Lubero territory, the FDLR appears to be relying on a new strategy – terrorizing the ethnic Nande population, which it had lived largely peacefully with before.

"The FDLR have a very ugly past, but we haven't seen this level of violence in years," adds Ms. Van Woudenberg. "They are deliberately targeting civilians [as]reprisals for the military operations."

In Luofo, a village about 80 miles north of Goma, five children were burned alive when 255 homes were torched on April 17.

One grieving father, his one remaining son at his side, says he lost his three other children as the militia stopped him from entering his house to rescue them. But his anger is not just directed at the militia. "We need peace in this area, but this is also a problem of our government, which does not care for the population," he says.

Luofo is not the only village to have been torched.

"People are telling us that thousands of homes have been burned," says Marcel Stoessel, country director of British aid agency Oxfam.

The increased violence is leading some to ask whether the Congolese government and the UN will be forced to scale down the military offensive in order not to provoke the FDLR into killing more civilians for revenge.

"Protection of civilians is our number one priority," claims the UN's Colonel Dietrich. "But we are also engaged in operations against the militia, supporting the Congolese Army. We are stretched to the maximum."

A new front opening?

Yet for now at least, such reservations haven't stopped the Congolese Army or the UN gearing up to open a new front.

The sphere of operations was restricted to North Kivu, one of two mineral-rich provinces where the FDLR has strongholds.

Now, the focus is shifting to neighboring South Kivu Province, where 10,000 Congolese government troops have been amassed. Ahead of this new campaign, the UN is attempting to ensure that wages make their way through to troops. "Before, salaries have gone to commanders to distribute," explains Dietrich. "But now, every soldier should get an identity card, so it's much easier to identify them and pay them directly."

But there are doubts as to whether Congo's government can carry on funding the Army.

Effect of the global economic crisis

"Congo's economy has been one of the worst affected in Africa by the global economic downturn," says Lisa Lewin, an economist for Business Monitor International, a London-based risk consultancy. "With commodity prices having plunged, we believe Congo will experience a recession this year."

Much of Congo's official revenue comes from copper, which, despite a recent bounce, is trading at only half the level it reached last July. This makes it even harder for the cash-strapped government to pay its soldiers.

And in a further cruel twist of economic fate, gold prices are buoyant, as global investors have been attracted by the metal's 'safe haven' status. And the FDLR is not only reclaiming gold-mining interests in North Kivu, but it also retains interests in the metal in South Kivu, where its networks remain intact, according to the Western official.

Meanwhile, the Tutsi-dominated government of Rwanda is sitting on the sidelines. Could it be tempted to intervene again if the offensive against its enemy, the FDLR, unravels? For now, Rwanda's President Paul Kagame is maintaining the spirit of good neighborliness and cooperation. He doesn't rule out sending troops back across the border, but says he will only help if the Congolese government asks him to.